The present invention relates to a connector having a mechanism for pressing contacts against a flexible printed circuit board or flexible flat cable for use in a mobile phone or cellular phone, notebook personal computer, digital camera and the like, and more particularly to a connector capable of inserting contacts in parallel with insertion grooves of its housing.
Among the connectors for use in mobile phones, charge couples device (CCD) cameras and the like, connectors of one kind mainly comprise a housing and contacts, and a flexible printed circuit board is inserted into the housing to be brought into contact with contact portions of the contacts. This type of connectors is so-called “non-zero-insertion force” (NZIF) type. The connectors of the other kind mainly comprise a housing, contacts and a slider so that a flexible printed circuit board is embraced by the housing and the slider. The connectors of this type are so-called “zero-insertion force” (ZIF) type or “piano touch” type. There may be various methods for holding the flexible printed circuit board by the housing and the slider. In many cases, after a flexible printed circuit board has been inserted into the housing, the slider is inserted to press the board against the contacts, or after a flexible printed circuit board has been inserted, the slider is pivotally moved to press the board against the contacts.
The housing is formed with a required number of insertion grooves into which the contacts are inserted and further formed with a fitting opening into which a flexible printed circuit board is inserted.
The contacts each mainly comprise a contact portion adapted to contact a flexible printed circuit board, a connection portion to be connected to a hard board or the like, and a fixed portion to be fixed to the housing. These contacts are fixed to the housing as by press-fitting.
Typically shown are a patent literature 1 (Japanese Utility Model Application Opened No. H6-60,983/1994) for the Z1F type connector and a patent literature 2 (Japanese Patent Application Opened No. H13-257,020/2001) for the piano touch type connector. The applicant of the present application has proposed a connector disclosed in a patent literature 3 (Japanese Patent Application No. 224,340/2002) which is capable of securely pressing a flexible printed circuit board or flexible flat cable against contact portions of contacts and is able to achieve even narrower pitches of contacts and minimization of height or lower geometry.
Patent Literature 1
Japanese Utility Model Application Opened No. H6-60,983/1994 discloses one example of the “zero-insertion force” type connectors. As can be seen from the “Abstract” of the Japanese Utility Model, this invention relates to a connector with a slider for a print board for use in a narrow space in an electronic or communication appliance. The slider is formed at the ends on both sides with U-shaped arms with their proximal ends fixed to the slider as guiding means when being inserted into a housing. The U-shaped arms are each provided on its opening side with a projection and formed with a notch such that the opening end is visible from the inserting side. The housing is provided at both the ends with projections having an oblique surface adapted to engage the projection of the slider. When the slider together with connection terminals of a flexible printed circuit board is inserted into the housing, the projections of the slider ride over the projections having the oblique surface of the housing so that the opening ends of the U-shaped arms of the slider are temporarily spread outwardly and then returned to their normal positions when the insertion has been completed.
Patent Literature 2
Japanese Patent Application Opened No. H13-257,020/2001 discloses one example of the so-called “piano touch” type connectors. With a view to obtaining an accurate positioning of a flexible printed circuit board or flexible flat cable relative to contacts of the disclosed connector, projections are provided in a row on a line on a terminal block between the contacts. After the flexible printed circuit board or flexible flat cable has been inserted into the terminal block, a slider is moved to press the circuit board or flat cable against the contacts. At the moment when the circuit board or flat cable is thus electrically connected to the contacts with the aid of the slider in this manner, the projections snap into recesses between patterns of the circuit board or flat cable, thereby ensuring positional coincidence between the contacts and patterns of the circuit board or flat cable.
Patent Literature 3
The Japanese Patent Application Opened No. 224,340/2002 discloses a connector which is capable of securely pressing a flexible printed circuit board or flexible flat cable against contact portions of contacts by a slider without degrading strength of respective parts and without detracting specifications, and which is superior in operationality or easy to use and easy to achieve narrower pitches of contacts and minimization of height or lower geometry of the connector. For the purpose of the lower geometry of the connector, the contacts each comprise an elastic portion and a fulcrum portion between the contact portion and a connection portion, and a pressure receiving portion at a position opposite to the connection portion and extending from the elastic portion, and the contact portion, the elastic portion, the fulcrum portion and the connection portion are arranged in the form of a crank. Moreover, the slider is provided with urging portions continuously in its longitudinal direction and is fitted in a housing so that the urging portions can be pivotally movable between the connection portions and the pressure receiving portions of the contacts.
In recent years, with miniaturization of electrical and electronic appliances, the requirement for the lower vertical geometry or minimization of height has put even more severe requirement on the connectors of this kinds using the flexible printed circuit board or flexible flat cable. With the connectors having the general construction, as is found in the patent literature 3, there are six layers in height, that is, the upper and lower walls of the housing, the contact portion and the pressure receiving portion of each of the contacts, the urging portion of the slider and the flexible printed circuit board or flexible flat cable. In order to reduce the connector's height as much as possible, it is possible to omit the pressure receiving portion of each of the contacts to obtain five layers in height (the upper and lower walls of the housing, the contact portion of each of the contacts, the urging portion of the slider and the flexible printed circuit board or flexible flat cable). It is however impossible to more reduce the height of the connector in consideration of strength of the respective members and specifications or customer's demands. Moreover, the insertion of the circuit board or flat cable and urging of the contact portions of the contacts against the circuit board or flat cable take place only on the side of the fitting opening of the housing for the circuit board or flat cable, so that as the connector is miniaturized, such operations would become more difficult. In order to overcome such problems, the applicant has proposed the connector disclosed in the patent literature 3, which is capable of securely pressing the contact portions of the contacts against the flexible printed circuit board or flat cable without degrading the strength of the respective members and without detracting specifications and is superior in operationality or easy to use and easy to achieve narrower pitches of contacts and minimization of height or lower geometry of the connector.
With the construction of the connector as disclosed in the patent literature 3, however, when the contacts are inserted into the housing, the contacts are obliquely inserted with their contact portions relative to the wall of the housing in amount corresponding to clearances between the contacts and insertion grooves of the housing, resulting in irregular contact pressures, making the contact between the contacts and the board unstable. This problem remains to be solved.